Display device

ABSTRACT

A display device includes: a plurality of first electrodes arranged in a display region for displaying an image; a second electrode opposed to the first electrodes; a plurality of switching elements that are arranged in the display region and coupled to the first electrodes or the second electrode; a gate line for supplying a scanning signal for scanning the switching elements; a data line for supplying a signal to the switching elements that are coupled to the switching elements; and conductive wire that is opposed to the second electrode via an insulating layer and is coupled to the switching elements.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of application Ser. No.16/205,955, filed Nov. 30, 2018, which, in turn, is a continuationapplication of application Ser. No. 15/400,498, (now U.S. Pat. No.10,175,816) filed Jan. 6, 2017, which in turn claims priority fromJapanese Application No. 2016-018365, filed on Feb. 2, 2016, thecontents of which are incorporated by reference herein in its entirety.

BACKGROUND 1. Technical Field

The present disclosure relates to a display device.

2. Description of the Related Art

Japanese Patent Application Laid-open Publication No. 2013-254219(JP-A-2013-254219) discloses a liquid crystal display panel including apixel electrode, a common electrode opposed to the pixel electrode, aswitching element coupled to the pixel electrode, and a conductive layerarranged on a surface of the common electrode. In the liquid crystaldisplay panel disclosed in JP-A-2013-254219, the conductive layer havingfavorable electrical conductivity is arranged on the common electrode,thereby reducing an apparent resistance value of the common electrodeand suppressing a flicker and crosstalk.

To the switching element arranged in a display region, coupled are agate line for supplying a scanning signal and a data line for supplyinga pixel signal. To increase a screen size of the display device orachieve high definition thereof, a large number of wires such as thegate line and the data line are arranged in the display region, so thatrestriction on an arrangement of wire may be increased. When suchelectrodes are used for touch detection, restriction on the wire or theswitching element may be further increased. JP-A-2013-254219 does notdescribe a case of using the conductive layer as the wire such as thegate line or the data line.

SUMMARY

According to an aspect, a display device includes a plurality of firstelectrodes arranged in a display region for displaying an image, asecond electrode opposed to the first electrodes, a plurality ofswitching elements that are arranged in the display region and coupledto the first electrodes or the second electrode, a gate line coupled tothe switching elements and for supplying a scanning signal for scanningthe switching elements, a data line for supplying a signal to theswitching elements, and a conductive wire that is opposed to the secondelectrode via an insulating layer and is coupled to the switchingelements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating a configuration example of adisplay device with a touch detection function according to a firstembodiment;

FIG. 2 is an explanatory diagram representing a state in which a fingeris in a non-contact state or a non-proximate state for explaining abasic principle of mutual capacitance touch detection;

FIG. 3 is an explanatory diagram illustrating an example of anequivalent circuit of the state in which the finger is in a non-contactstate or a non-proximate state as illustrated in FIG. 2;

FIG. 4 is an explanatory diagram representing a state in which thefinger is in a contact state or a proximate state for explaining thebasic principle of mutual capacitance touch detection;

FIG. 5 is an explanatory diagram illustrating an example of anequivalent circuit of the state in which the finger is in a contactstate or a proximate state as illustrated in FIG. 4;

FIG. 6 is a diagram representing an example of waveforms of a drivesignal and a touch detection signal in mutual capacitance touchdetection;

FIG. 7 is an explanatory diagram representing the state in which thefinger is in a non-contact state or a non-proximate state for explaininga basic principle of self capacitance touch detection;

FIG. 8 is an explanatory diagram representing the state in which thefinger is in a contact state or a proximate state for explaining thebasic principle of self capacitance touch detection;

FIG. 9 is an explanatory diagram illustrating an example of anequivalent circuit of self capacitance touch detection;

FIG. 10 is a diagram representing an example of waveforms of a drivesignal and a touch detection signal in self capacitance touch detection;

FIG. 11 is a cross-sectional view representing a schematiccross-sectional structure of the display device with a touch detectionfunction;

FIG. 12 is a plan view schematically illustrating a TFT substrateconfiguring the display device with a touch detection function;

FIG. 13 is a plan view schematically illustrating a glass substrateconfiguring the display device with a touch detection function;

FIG. 14 is a circuit diagram representing a pixel array of a displayunit with a touch detection function according to the first embodiment;

FIG. 15 is a perspective view representing a configuration example of adrive electrode and a touch detection electrode of the display unit witha touch detection function according to the first embodiment;

FIG. 16 is a schematic diagram representing an example of arrangement ofa display period and a touch period within one frame period;

FIG. 17 is a plan view for explaining a configuration of a pixelelectrode and a switching element for display of a display panelaccording to the first embodiment;

FIG. 18 is a plan view of the TFT substrate for explaining aconfiguration of a sub-pixel;

FIG. 19 is a cross-sectional view along the line XIX-XIX′ in FIG. 18;

FIG. 20 is a plan view illustrating a pixel substrate according to asecond embodiment;

FIG. 21 is a plan view for explaining a configuration of a pixelelectrode and a switching element for display according to the secondembodiment;

FIG. 22 is a plan view of the TFT substrate for explaining aconfiguration of the sub-pixel in a first display region according tothe second embodiment;

FIG. 23 is a cross-sectional view along the line XXIII-XXIII′ in FIG.22;

FIG. 24 is a plan view of the TFT substrate for explaining aconfiguration of the sub-pixel in a second display region according tothe second embodiment;

FIG. 25 is a cross-sectional view along the line XXV-XXV′ in FIG. 24;

FIG. 26 is a plan view for explaining a coupling structure between adisplay control IC and wires;

FIG. 27 is a plan view for explaining a coupling structure between thedrive electrode and a switching element for touch according to a thirdembodiment;

FIG. 28 is a plan view for explaining a configuration of the driveelectrode and the pixel electrode according to the third embodiment;

FIG. 29 is a cross-sectional view along the line XXIX-XXIX′ in FIG. 28;

FIG. 30 is a timing waveform chart illustrating an operation example ofa display device with a touch detection function according to the thirdembodiment;

FIG. 31 is a plan view illustrating a configuration example of a gatedriver according to the third embodiment;

FIG. 32 is a plan view illustrating another configuration example of thegate driver according to the third embodiment;

FIG. 33 is a plan view illustrating a light shielding part of a displaydevice with a touch detection function according to a modification ofthe third embodiment;

FIG. 34 is a cross-sectional view along the line XXXIV-XXXIV′ in FIG.33;

FIG. 35 is a plan view illustrating a configuration example of a driveelectrode and a drive electrode driver according to a fourth embodiment;

FIG. 36 is a cross-sectional view illustrating a coupling point betweenthe drive electrode and a conductive wire;

FIG. 37 is a plan view of a drive electrode and a drive circuitaccording to a fifth embodiment;

FIG. 38 is a timing waveform chart illustrating an operation example ofa display device with a touch detection function according to the fifthembodiment;

FIG. 39 is a plan view illustrating a configuration example of a driveelectrode and a conductive wire according to a modification of the fifthembodiment;

FIG. 40 is a block diagram illustrating a configuration example of adisplay device with a touch detection function according to a sixthembodiment;

FIG. 41 is a plan view of a drive electrode and a drive circuitaccording to the sixth embodiment; and

FIG. 42 is a timing waveform chart illustrating an operation example ofthe display device with a touch detection function according to thesixth embodiment.

DETAILED DESCRIPTION

The following describes embodiments in detail with reference to thedrawings. The present invention is not limited to the embodimentsdescribed below. Components described below include a component that iseasily conceivable by those skilled in the art and substantially thesame component. The components described below can be appropriatelycombined. The disclosure is merely an example, and the present inventionnaturally encompasses an appropriate modification maintaining the gistof the invention that is easily conceivable by those skilled in the art.To further clarify the description, the width, the thickness, the shape,and the like of each component may be schematically illustrated in thedrawings as compared with an actual aspect. However, the drawings merelyprovide examples, and are not intended to limit interpretation of theinvention. The same element as that described in the drawing alreadydiscussed is denoted by the same reference numeral throughout thedescription and the drawings, and detailed description thereof will notbe repeated in some cases.

First Embodiment

FIG. 1 is a block diagram illustrating a configuration example of adisplay device with a touch detection function according to a firstembodiment. As illustrated in FIG. 1, a display device 1 with a touchdetection function includes a display unit 10 with a touch detectionfunction, a control unit 11, a gate driver 12, a source driver 13, adrive electrode driver 14, and a touch detection unit 40. In the displaydevice 1 with a touch detection function, a touch detection function isincorporated in the display unit 10 with a touch detection function. Thedisplay unit 10 with a touch detection function is a device integratinga display panel 20 including a liquid crystal display element as adisplay element with a touch panel 30 serving as a touch detectiondevice for detecting a touch input. The display unit 10 with a touchdetection function may be what is called an on-cell device in which thetouch panel 30 is mounted on the display panel 20. The display panel 20may be, for example, an organic EL display panel.

As described later, the display panel 20 is an element that sequentiallyperforms scanning for each horizontal line to perform display inaccordance with a scanning signal Vscan supplied from the gate driver12. The control unit 11 is a circuit that supplies a control signal toeach of the gate driver 12, the source driver 13, the drive electrodedriver 14, and the touch detection unit 40 based on a video signal Vdispsupplied from the outside to control these components to operate insynchronization with each other.

The gate driver 12 has a function of sequentially selecting onehorizontal line to be a display driving target of the display unit 10with a touch detection function based on the control signal suppliedfrom the control unit 11.

The source driver 13 is a circuit that supplies a pixel signal Vpix toeach sub-pixel SPix (described later) in the display unit 10 with atouch detection function based on the control signal supplied from thecontrol unit 11.

The drive electrode driver 14 is a circuit that supplies a drive signalVcom to a drive electrode COML (described later) in the display unit 10with a touch detection function based on the control signal suppliedfrom the control unit 11.

The touch panel 30 operates based on a basic principle of capacitancetouch detection, and performs a touch detection operation using a mutualcapacitance system to detect contact or proximity of an externalconductor to a display region. The touch panel 30 may perform a touchdetection operation using a self capacitance system.

The touch detection unit 40 is a circuit that detects whether there is atouch on the touch panel 30 based on the control signal supplied fromthe control unit 11 and a touch detection signal Vdet1 supplied from thetouch panel 30. The touch detection unit 40 obtains coordinates at whicha touch input is performed when there is a touch. The touch detectionunit 40 includes a touch detection signal amplification unit 42, an A/Dconversion unit 43, a signal processing unit 44, and a coordinateextracting unit 45. A detection timing control unit 46 controls the A/Dconversion unit 43, the signal processing unit 44, and the coordinateextracting unit 45 to operate in synchronization with each other basedon the control signal supplied from the control unit 11.

As described above, the touch panel 30 operates based on the basicprinciple of capacitance touch detection. With reference to FIGS. 2 to6, the following describes the basic principle of mutual capacitancetouch detection performed by the display device 1 with a touch detectionfunction according to the present embodiment. FIG. 2 is an explanatorydiagram representing a state in which a finger is in a non-contact stateor a non-proximate state for explaining the basic principle of mutualcapacitance touch detection. FIG. 3 is an explanatory diagramillustrating an example of an equivalent circuit of the state in whichthe finger is in a non-contact state or a non-proximate state asillustrated in FIG. 2. FIG. 4 is an explanatory diagram representing astate in which the finger is in a contact state or a proximate state forexplaining the basic principle of mutual capacitance touch detection.FIG. 5 is an explanatory diagram illustrating an example of anequivalent circuit of the state in which the finger is in a contactstate or a proximate state as illustrated in FIG. 4. FIG. 6 is a diagramrepresenting an example of waveforms of the drive signal and the touchdetection signal. The following describes a case in which the finger isbrought into contact with or proximate to the touch panel.Alternatively, for example, an object including a conductor such as astylus pen may be replaced with the finger.

For example, as illustrated in FIG. 2, a capacitive element C1 includesa pair of electrodes arranged to be opposed to each other with adielectric D interposed therebetween, that is, a drive electrode E1 anda touch detection electrode E2. As illustrated in FIG. 3, one end of thecapacitive element C1 is coupled to an AC signal source (drive signalsource) S, and the other end thereof is coupled to a voltage detectorDET. The voltage detector DET is, for example, an integrating circuitincluded in the touch detection signal amplification unit 42 illustratedin FIG. 1.

When an AC rectangular wave Sg having a predetermined frequency (forexample, about several kHz to several hundreds kHz) is applied to thedrive electrode E1 (one end of the capacitive element C1) from the ACsignal source S, an output waveform (touch detection signal Vdet1) asillustrated in FIG. 6 appears via the voltage detector DET coupled tothe touch detection electrode E2 (the other end of the capacitiveelement C1). The AC rectangular wave Sg corresponds to the drive signalVcom input from the drive electrode driver 14.

In a state in which the finger is not in contact with or proximate tothe touch panel (non-contact state), as illustrated in FIGS. 2 and 3, acurrent I₀ corresponding to a capacitance value of the capacitiveelement C1 flows in accordance with charge and discharge of thecapacitive element C1. The voltage detector DET illustrated in FIG. 3converts variation in the current I₀ corresponding to the AC rectangularwave Sg into variation in a voltage (a waveform V₀ of a solid line(refer to FIG. 6)).

In a state in which the finger is in contact with or proximate to thetouch panel (contact state), as illustrated in FIG. 4, capacitance C2generated by the finger is in contact with or proximate to the touchdetection electrode E2, so that capacitance corresponding to a fringebetween the drive electrode E1 and the touch detection electrode E2 isshielded. Due to this, as illustrated in FIG. 5, the capacitive elementC1 functions as a capacitive element C1′ having a capacitance valuesmaller than the capacitance value in a non-contact state. Withreference to the equivalent circuit illustrated in FIG. 5, a current I₁flows through the capacitive element C1′. As illustrated in FIG. 6, thevoltage detector DET converts variation in the current I₁ correspondingto the AC rectangular wave Sg into variation in the voltage (a waveformV₁ of a dotted line). In this case, amplitude of the waveform V₁ issmaller than that of the waveform V₀ described above. Accordingly, anabsolute value |ΔV| of a voltage difference between the waveform V₀ andthe waveform V₁ varies depending on influence of a conductor such as afinger that is brought into contact with or proximate to the touch panelfrom the outside. To accurately detect the absolute value |ΔV| of thevoltage difference between the waveform V₀ and the waveform V₁ it ismore preferable to provide, to an operation of the voltage detector DET,a period Reset for resetting charge and discharge of a capacitor inaccordance with a frequency of the AC rectangular wave Sg throughswitching in the circuit.

The touch panel 30 illustrated in FIG. 1 sequentially performs scanningfor each detection block in accordance with the drive signal Vcomsupplied from the drive electrode driver 14 to perform mutualcapacitance touch detection.

The touch panel 30 outputs the touch detection signal Vdet1 for eachdetection block via the voltage detector DET illustrated in FIG. 3 orFIG. 5 from a plurality of touch detection electrodes TDL describedlater. The touch detection signal Vdet1 is supplied to the touchdetection signal amplification unit 42 of the touch detection unit 40.

The touch detection signal amplification unit 42 amplifies the touchdetection signal Vdet1 supplied from the touch panel 30. The touchdetection signal amplification unit 42 may include an analog low passfilter (LPF) serving as a low-pass analog filter that removes a highfrequency component (noise component) included in the touch detectionsignal Vdet1 and outputs the result.

The A/D conversion unit 43 samples each analog signal output from thetouch detection signal amplification unit 42 at a timing synchronizedwith the drive signal Vcom, and converts the analog signal into adigital signal.

The signal processing unit 44 includes a digital filter that reduces afrequency component (noise component) included in the output signal ofthe A/D conversion unit 43, other than a frequency at which the drivesignal Vcom is sampled. The signal processing unit 44 is a logic circuitthat detects whether there is a touch on the touch panel 30 based on theoutput signal of the A/D conversion unit 43. The signal processing unit44 performs processing of extracting only a difference of the detectionsignal caused by the finger. The signal of the difference caused by thefinger has the absolute value |ΔV| of the difference between thewaveform V₀ and the waveform V₁ described above. The signal processingunit 44 may perform an arithmetic operation for averaging the absolutevalue |ΔV| for each detection block to obtain an average value of theabsolute value |ΔV|. Due to this, the signal processing unit 44 cansuppress influence of the noise. The signal processing unit 44 comparesthe detected signal of the difference caused by the finger with apredetermined threshold voltage. If the signal of the difference issmaller than the threshold voltage, the signal processing unit 44determines that an external proximity object is in a non-contact state.On the other hand, the signal processing unit 44 compares the detectedsignal of the difference caused by the finger with the predeterminedthreshold voltage. If the signal of the difference is equal to or largerthan the threshold voltage, the signal processing unit 44 determinesthat the external proximity object is in a contact state. In this way,the touch detection unit 40 can perform touch detection.

The coordinate extracting unit 45 is a logic circuit that obtains, whena touch is detected by the signal processing unit 44, touch panelcoordinates at which the touch is detected. The coordinate extractingunit 45 outputs the touch panel coordinates as a detection signal outputVout. As described above, the display device 1 with a touch detectionfunction according to the present embodiment can perform the touchdetection operation based on the basic principle of mutual capacitancetouch detection.

Next, the following describes a basic principle of self capacitancetouch detection with reference to FIGS. 7 to 10. FIG. 7 is anexplanatory diagram representing the state in which the finger is in anon-contact state or a non-proximate state for explaining the basicprinciple of self capacitance touch detection. FIG. 8 is an explanatorydiagram representing the state in which the finger is in a contact stateor a proximate state for explaining the basic principle of selfcapacitance touch detection. FIG. 9 is an explanatory diagramillustrating an example of an equivalent circuit of self capacitancetouch detection. FIG. 10 is a diagram representing an example ofwaveforms of a drive signal and a touch detection signal in selfcapacitance touch detection.

In the state in which the finger is in a non-contact state or anon-proximate state, the left figure of FIG. 7 illustrates a state inwhich a power source Vdd is coupled to the touch detection electrode E2via a switch SW1 and the touch detection electrode E2 is not coupled toa capacitor Ccr via a switch SW2. In this state, capacitance Cx1included in the touch detection electrode E2 is charged. The rightfigure of FIG. 7 illustrates a state in which the power source Vdd isdisconnected from the touch detection electrode E2 via the switch SW1and the touch detection electrode E2 is coupled to the capacitor Ccr viathe switch SW2. In this state, an electric charge of the capacitance Cx1is discharged via the capacitor Ccr.

In the state in which the finger is in a contact state or a proximatestate, the left figure of FIG. 8 illustrates a state in which the powersource Vdd is coupled to the touch detection electrode E2 via the switchSW1 and the touch detection electrode E2 is not coupled to the capacitorCcr via the switch SW2. In this state, capacitance Cx2 caused by thefinger that is proximate to the touch detection electrode E2 is chargedin addition to the capacitance Cx1 included in the touch detectionelectrode E2. The right figure of FIG. 8 illustrates a state in whichthe power source Vdd is disconnected from the touch detection electrodeE2 via the switch SW1 and the touch detection electrode E2 is coupled tothe capacitor Ccr via the switch SW2. In this state, the electric chargeof the capacitance Cx1 and an electric charge of the capacitance Cx2 aredischarged via the capacitor Ccr.

A voltage change characteristic of the capacitor Ccr during discharge(in the state in which the finger is in a contact state or a proximatestate) illustrated in the right figure of FIG. 8 is obviously differentfrom the voltage change characteristic of the capacitor Ccr duringdischarge (in the state in which the finger is in a non-contact state ora non-proximate state) illustrated in the right figure of FIG. 7 due topresence of the capacitance Cx2. Thus, in a self capacitance system,whether there is an operation input by a finger and the like isdetermined by utilizing the fact that the voltage change characteristicof the capacitor Ccr varies depending on the presence or absence of thecapacitance Cx2.

Specifically, AC rectangular wave Sg (refer to FIG. 10) having apredetermined frequency (for example, about several kHz to severalhundreds kHz) is applied to the touch detection electrode E2. Thevoltage detector DET illustrated in FIG. 9 converts variation in acurrent corresponding to the AC rectangular wave Sg into variation in avoltage (waveforms V₄ and V₅).

As described above, the touch detection electrode E2 is configured to bedisconnectable with the switch SW1 and the switch SW2. In FIG. 10, at atiming of time T₀₁, the AC rectangular wave Sg raises a voltage levelcorresponding to a voltage V₀. At this point, the switch SW1 is in an ONstate and the switch SW2 is in an OFF state. Due to this, the voltage ofthe touch detection electrode E2 is raised to be the voltage V₀. Next,the switch SW1 is turned OFF before a timing of time T₁₁. Although thetouch detection electrode E2 is in a floating state at this point, theelectric potential of the touch detection electrode E2 is kept at V₀with the capacitance Cx1 (refer to FIG. 7) of the touch detectionelectrode E2 or the capacitance (Cx1+Cx2, refer to FIG. 8) obtained byadding the capacitance Cx2 generated by contact or proximity of a fingerand the like to the capacitance Cx1 of the touch detection electrode E2.The switch SW3 is turned ON before the timing of time T₁₁, and turnedOFF after a predetermined time has elapsed to reset the voltage detectorDET. Through this reset operation, the output voltage becomessubstantially the same voltage as Vref.

Subsequently, when the switch SW2 is turned ON at the timing of timeT₁₁, a reverse input unit of the voltage detector DET has the voltage V₀of the touch detection electrode E2. Thereafter, the voltage of thereverse input unit of the voltage detector DET is lowered to a referencevoltage Vref in accordance with a time constant of the capacitance Cx1(or Cx1+Cx2) of the touch detection electrode E2 and capacitance C5 inthe voltage detector DET. At this point, an electric charge accumulatedin the capacitance Cx1 (or Cx1+Cx2) of the touch detection electrode E2moves to the capacitance C5 in the voltage detector DET, so that theoutput of the voltage detector DET is increased (Vdet2). The output(Vdet2) of the voltage detector DET is represented as the waveform V₄ ofa solid line when a finger and the like are not proximate to the touchdetection electrode E2, and Vdet2=Cx1×V₀/C5 is satisfied. Whencapacitance caused by a finger and the like is added, the output (Vdet2)is represented as the waveform V₅ of a dotted line, andVdet2=(Cx1+Cx2)×V₀/C5 is satisfied.

Thereafter, at a timing of time T₃₁ after the electric charge of thecapacitance Cx1 (or Cx1+Cx2) of the touch detection electrode E2sufficiently moves to the capacitance C5, the switch SW2 is turned OFFand the switch SW1 and the switch SW3 are turned ON, and thus theelectric potential of the touch detection electrode E2 is caused to beat a low level that is the same as the electric potential of the ACrectangular wave Sg, and the voltage detector DET is reset. In thiscase, a timing for turning ON the switch SW1 may be any timing after theswitch SW2 is turned OFF and before time T₀₂. A timing for resetting thevoltage detector DET may be any timing after the switch SW2 is turnedOFF and before time T₁₂. The above operation is repeated at apredetermined frequency (for example, about several kHz to severalhundreds kHz). It can be measured whether there is an external proximityobject (whether there is a touch) based on an absolute value |ΔV| of adifference between the waveform V₄ and the waveform V₅. As illustratedin FIG. 10, the electric potential of the touch detection electrode E2is represented as the waveform V₂ when a finger and the like are in anon-proximate state, and represented as the waveform V₃ when thecapacitance Cx2 caused by a finger and the like is added. As a detectionmethod, for example, it can be measured whether there is an externalproximity object (whether there is a touch) by measuring a time untileach of the waveform V₂ and the waveform V₃ is lowered to apredetermined voltage V_(TH).

Next, the following describes a configuration example of the displaydevice 1 with a touch detection function in detail. FIG. 11 is across-sectional view representing a schematic cross-sectional structureof the display device with a touch detection function. FIG. 12 is a planview schematically illustrating a TFT substrate configuring the displaydevice with a touch detection function. FIG. 13 is a plan viewschematically illustrating a glass substrate configuring the displaydevice with a touch detection function.

As illustrated in FIG. 11, the display device 1 with a touch detectionfunction includes a pixel substrate 2, a counter substrate 3 arranged tobe opposed to a surface of the pixel substrate 2 in a perpendiculardirection, and a liquid crystal layer 6 interposed between the pixelsubstrate 2 and the counter substrate 3.

As illustrated in FIG. 11, the pixel substrate 2 includes a thin filmtransistor (TFT) substrate 21 serving as a circuit board, a plurality ofpixel electrodes 22 arranged in a matrix above the TFT substrate 21, aplurality of drive electrodes COML arranged between the TFT substrate 21and the pixel electrodes 22, and an insulating layer 24 that insulatesthe pixel electrode 22 from the drive electrode COML. A polarizing plate35B may be arranged under the TFT substrate 21 with a bonding layerinterposed therebetween (not illustrated).

As illustrated in FIG. 12, the TFT substrate 21 includes a displayregion 10 a for displaying an image and a frame region 10 b arrangedaround the display region 10 a. The display region 10 a has arectangular shape having a pair of long sides and a pair of short sides.The frame region 10 b has a frame shape surrounding four sides of thedisplay region 10 a.

The drive electrodes COML are arranged in the display region 10 a of theTFT substrate 21, and arrayed in a matrix in a direction along the longside of the display region 10 a and a direction along the short sidethereof. Each of the drive electrodes COML has a rectangular shape or asquare shape. The drive electrode COML is made of, for example, atranslucent conductive material such as indium tin oxide (ITO). Aplurality of pixel electrodes 22 are arranged in a matrix at a positioncorresponding to one drive electrode COML. An area of the pixelelectrode 22 is smaller than that of the drive electrode COML. AlthoughFIG. 12 illustrates part of the drive electrodes COML and the pixelelectrodes 22, the drive electrodes COML and the pixel electrodes 22 arearranged over the entire display region 10 a. In the present embodiment,a plurality of drive electrodes COML arranged in a row direction may bedriven at the same time, serving as one drive electrode block COMLA.

The drive electrode driver 14 and a display control IC 19 are arrangedon the short side of the frame region 10 b of the TFT substrate 21. Aflexible substrate (not illustrated) is coupled to the short side of theframe region 10 b, and is coupled to the display control IC 19 and/orthe drive electrode driver 14. Wires 37 are coupled to the respectivedrive electrodes COML, and are drawn out to the short side of the frameregion 10 b. The drive electrode driver 14 is coupled to each of thedrive electrodes COML via the wires 37 arranged in the display region 10a. Due to this, the drive electrode driver 14 is not required to bearranged on the long side of the frame region 10 b, so that the width ofthe frame region 10 b on the long side can be reduced.

The display control IC 19 is a chip mounted on the TFT substrate 21using a chip on glass (COG) system, and incorporates the control unit 11described above. The display control IC 19 outputs a control signal to agate line GCL for display, a data line SGL for display (describedlater), and the like based on the video signal Vdisp (refer to FIG. 1)supplied from an external host IC (not illustrated).

As illustrated in FIG. 11, the counter substrate 3 includes a glasssubstrate 31 and a color filter 32 formed on one face of the glasssubstrate 31. The touch detection electrode TDL serving as a detectionelectrode of the touch panel 30 is arranged on the other face of theglass substrate 31. A polarizing plate 35A is arranged above the touchdetection electrode TDL with a bonding layer interposed therebetween(not illustrated). A flexible substrate (not illustrated) is coupled tothe glass substrate 31. The flexible substrate is coupled to the touchdetection electrode TDL via the frame wire.

As illustrated in FIG. 13, a plurality of touch detection electrodes TDLare arranged in the display region 10 a of the glass substrate 31. Thetouch detection electrodes TDL each extend in a direction along the longside of the display region 10 a, and are arrayed in a direction alongthe short side of the display region 10 a. Each touch detectionelectrode TDL includes two detection electrodes TDLa and TDLb, andcoupling parts TDLc and TDLc that couple the detection electrode TDLa tothe detection electrode TDLb. The two detection electrodes TDLa and TDLbextend in the direction along the long side of the display region 10 aand parallel with each other. The coupling parts TDLc are arranged onboth ends of the detection electrodes TDLa and TDLb.

As illustrated in FIG. 11, the TFT substrate 21 and the glass substrate31 are arranged to be opposed to each other with a predetermined gaptherebetween. The liquid crystal layer 6 is arranged in a space betweenthe TFT substrate 21 and the glass substrate 31. The liquid crystallayer 6 modulates light passing therethrough depending on a state of anelectric field. For example, used are liquid crystals of lateralelectric-field mode such as in-plane switching (IPS) including fringefield switching (FFS). An orientation film may be arranged between theliquid crystal layer 6 and the pixel substrate 2, and between the liquidcrystal layer 6 and the counter substrate 3 illustrated in FIG. 11.

Next, the following describes a display operation of the display panel20. FIG. 14 is a circuit diagram representing a pixel array of thedisplay unit with a touch detection function according to the firstembodiment. In the TFT substrate 21 illustrated in FIG. 11, formed are aswitching element TrD for display of each sub-pixel SPix illustrated inFIG. 14, and wires such as the data line SGL for display for supplyingthe pixel signal Vpix to each pixel electrode 22 and the gate line GCLfor display for supplying a drive signal for driving each switchingelement TrD for display. The data line SGL for display and the gate lineGCL for display extend along a plane parallel with the surface of theTFT substrate 21.

The display panel 20 illustrated in FIG. 14 includes a plurality ofsub-pixels SPix arranged in a matrix. Each sub-pixel SPix includes theswitching element TrD for display and a liquid crystal element LC. Theswitching element TrD for display is constituted of a thin filmtransistor. In this example, the switching element TrD for display isconstituted of an n-channel metal oxide semiconductor (MOS) TFT. Asource of the switching element TrD for display is coupled to the dataline SGL for display, a gate thereof is coupled to the gate line GCL fordisplay, and a drain thereof is coupled to one end of the liquid crystalelement LC. In the equivalent circuit, one end of the liquid crystalelement LC including the liquid crystal layer 6 is coupled to the drainof the switching element TrD for display, and the other end thereof iscoupled to each drive electrode COML included in the drive electrodeblock COMLA. The insulating layer 24 is arranged between the pixelelectrode 22 and the common electrode (drive electrode COML), whichforms holding capacitance Cs illustrated in FIG. 14.

The sub-pixel SPix is mutually coupled to the other sub-pixel SPixbelonging to the same row in the display panel 20 via the gate line GCLfor display. The gate line GCL for display is coupled to the gate driver12 (refer to FIG. 1), and receives the scanning signal Vscan suppliedfrom the gate driver 12. The sub-pixel SPix is mutually coupled to theother sub-pixel SPix belonging to the same column in the display panel20 via the data line SGL for display. The data line SGL for display iscoupled to the source driver 13 (refer to FIG. 1), and receives thepixel signal Vpix supplied from the source driver 13. Each driveelectrode COML included in the drive electrode block COMLA is coupled tothe drive electrode driver 14 (refer to FIG. 1), and receives the drivesignal Vcom supplied from the drive electrode driver 14.

The gate driver 12 illustrated in FIG. 1 drives the gate line GCL fordisplay to sequentially perform scanning. The gate driver 12 applies thescanning signal Vscan (refer to FIG. 1) to a gate of a TFT element Tr ofthe sub-pixel SPix via the gate line GCL for display. Accordingly, oneline (one horizontal line) of the sub-pixels SPix is sequentiallyselected as a display driving target. The source driver 13 supplies thepixel signal Vpix to the sub-pixels SPix belonging to the selected onehorizontal line via the data line SGL for display illustrated in FIG.14. In performing the display operation for each horizontal line asdescribed above, the drive electrode driver 14 applies the drive signalVcom (display drive signal Vcomdc) to the drive electrode COML. Due tothis, each drive electrode COML functions as a common electrode for thepixel electrode 22 at the time of display.

In the color filter 32 illustrated in FIG. 11, for example, colorregions of the color filter colored in three colors of red (R), green(G), and blue (B) may be periodically arranged. Color regions 32R, 32G,and 32B of three colors R, G, and B are associated, as one set, witheach of the sub-pixels SPix illustrated in FIG. 14, and a pixel Pix isconstituted of a set of sub-pixels SPix corresponding to the colorregions 32R, 32G, and 32B of three colors. As illustrated in FIG. 11,the color filter 32 is opposed to the liquid crystal layer 6 in adirection perpendicular to the TFT substrate 21. Another combination ofcolors may be used for the color filter 32 so long as the colors aredifferent from each other. The combination of colors for the colorfilter 32 is not limited to three colors. Alternatively, four or morecolors may be combined.

As illustrated in FIG. 14, in the present embodiment, the driveelectrode block COMLA including a plurality of drive electrodes COML isarranged along the gate line GCL for display. Alternatively, the driveelectrode block COMLA is arranged to intersect with the data line SGLfor display. The arrangement of the drive electrode block COMLA is notlimited thereto. The drive electrode block COMLA may be arranged alongthe data line SGL for display, for example.

The drive electrode COML illustrated in FIGS. 11 and 12 functions as acommon electrode that gives a common potential (reference potential) tothe pixel electrodes 22 of the display panel 20. The drive electrodeCOML also functions as a drive electrode for performing mutualcapacitance touch detection of the touch panel 30. The drive electrodeCOML may also function as a detection electrode for performing selfcapacitance touch detection of the touch panel 30. FIG. 15 is aperspective view representing a configuration example of the driveelectrode and the touch detection electrode of the display unit with atouch detection function according to the first embodiment. The touchpanel 30 is constituted of the drive electrode COML arranged in thepixel substrate 2 and the touch detection electrode TDL arranged in thecounter substrate 3.

The drive electrode block COMLA including a plurality of driveelectrodes COML functions as a plurality of stripe electrode patternsextending in a horizontal direction of FIG. 15. The touch detectionelectrode TDL includes a plurality of electrode patterns intersectingwith a plurality of drive electrode blocks COMLA. The touch detectionelectrode TDL is opposed to the drive electrode block COMLA in adirection perpendicular to the surface of the TFT substrate 21 (refer toFIG. 11). Each electrode pattern of the touch detection electrode TDL iscoupled to an input of the touch detection signal amplification unit 42(refer to FIG. 1). Capacitance is generated at each intersecting portionbetween each drive electrode COML of the drive electrode block COMLA andeach electrode pattern of the touch detection electrode TDL.

The shape of the touch detection electrode TDL and the drive electrodeCOML (drive electrode block COMLA) is not limited to a plurality ofstripes. For example, the touch detection electrode TDL may have acomb-teeth shape and the like. Alternatively, it is sufficient that thetouch detection electrode TDL is divided into a plurality of parts, anda slit that divides the drive electrode COML may have a linear shape ora curved shape.

When the touch panel 30 performs a mutual capacitance touch detectionoperation, the drive electrode block COMLA is sequentially scanned oneby one in a time division manner by the drive electrode driver 14.Accordingly, the drive electrode COML of the drive electrode block COMLAis sequentially selected. The touch detection signal Vdet1 is output tothe selected drive electrode block COMLA from the touch detectionelectrode TDL. The drive electrode block COMLA corresponds to the driveelectrode E1 in the basic principle of mutual capacitance touchdetection described above, and the touch detection electrode TDLcorresponds to the touch detection electrode E2. The touch panel 30detects a touch input in accordance with the basic principle. Asillustrated in FIG. 15, in the touch panel 30, the touch detectionelectrode TDL and the drive electrode block COMLA intersecting with eachother constitute a capacitance touch sensor in a matrix. Thus, bysequentially driving each drive electrode block COMLA, a position wherean external conductor is brought into contact with or proximate to thetouch panel 30 can be detected.

As an example of an operating method of the display device 1 with atouch detection function, the display device 1 with a touch detectionfunction performs a touch detection operation (touch period) and adisplay operation (display period) in a time division manner. The touchdetection operation and the display operation may be separatelyperformed in any manner. The following describes a method of performingthe touch detection operation and the display operation while dividingeach operation into a plurality of parts within one frame period (1Fperiod) of the display panel 20, that is, within time required fordisplaying video information corresponding to one screen.

FIG. 16 is a schematic diagram representing an example of arrangement ofthe display period and the touch period within one frame period. Oneframe period (1F) includes two display periods Pd1 and Pd2, and twotouch periods Pt1 and Pt2. These periods are arranged so that thedisplay period and the touch period are alternately set on a time axisas follows: the display period Pd1, the touch period Pt1, the displayperiod Pd2, and the touch period Pt2.

The control unit 11 (refer to FIG. 1) supplies pixel signals Vpix to aplurality of rows of pixels Pix (refer to FIG. 14) selected in each ofthe display periods Pd1 and Pd2 via the gate driver 12 and the sourcedriver 13.

The control unit 11 (refer to FIG. 1) supplies a drive signal Vcom fortouch detection (touch drive signal Vcomac) to the drive electrode COML(drive electrode block COMLA) (refer to FIG. 15) selected in each of thetouch periods Pt1 and Pt2 via the drive electrode driver 14. Based onthe touch detection signal Vdet1 supplied from the touch detectionelectrode TDL, the touch detection unit 40 detects whether there is atouch input and performs an arithmetic operation of coordinates of aninput position.

In the present embodiment, the drive electrode COML also functions as acommon electrode of the display panel 20. Thus, the control unit 11supplies the display drive signal Vcomdc having a common electrodepotential for display to the drive electrode COML in the display periodsPd1 and Pd2.

When touch detection is performed based on a change in self capacitanceof the drive electrode COML without using the touch detection electrodeTDL for the touch detection operation, the drive electrode driver 14supplies the touch drive signal Vcomac to each drive electrode COML, andbased on the touch detection signal Vdet2 supplied from each driveelectrode COML, the touch detection unit 40 detects whether there is atouch input and performs an arithmetic operation of coordinates of theinput position.

In FIG. 16, video display for one screen is assumed to be performedwhile being divided into two parts within one frame period (1F).Alternatively, the display period within one frame period (1F) may bedivided into a larger number of parts. The touch period may also bedivided into a larger number of parts within one frame period (1F).

In each of the touch periods Pt1 and Pt2, touch detection for a half ofone screen may be performed, or touch detection for one screen may beperformed. Thinning-out detection and the like may be performed asneeded. Each of the display operation and the touch detection operationmay be performed once within one frame period (1F) without being dividedinto a plurality of parts.

In the touch periods Pt1 and Pt2, the gate line GCL for display and thedata line SGL for display (refer to FIG. 14) may be in a floating statein which a voltage signal is not supplied and electric potential is notfixed. As described later, signals having the same waveform and beingsynchronized with the touch drive signal Vcomac may be supplied to thegate line GCL for display and the data line SGL for display.

Next, the following describes a detailed configuration of the displaypanel 20 according to the present embodiment. FIG. 17 is a plan view forexplaining a configuration of the pixel electrode and the switchingelement for the display panel according to the first embodiment.

As illustrated in FIG. 17, a plurality of pixel electrodes 22 arearranged in a matrix at a position overlapped with one drive electrodeCOML. The switching element TrD for display is arranged at a positioncorresponding to each of the pixel electrodes 22. A plurality of gatelines GCL for display each extend in a row direction, and are arrangedin a column direction. A plurality of data lines SGL for display eachextend in the column direction intersecting with an extending directionof the gate line GCL for display, and are arranged in the row direction.The switching element TrD for display is arranged at an intersectingpart of the gate line GCL for display and the data line SGL for display.A region surrounded by the gate line GCL for display and the data lineSGL for display is the sub-pixel SPix. The sub-pixel SPix is arranged toinclude a region where the pixel electrode 22 overlaps with the driveelectrode COML.

In the present embodiment, a conductive wire 51 is arranged at aposition overlapped with the data line SGL for display. A plurality ofconductive wires 51 each extend in the column direction that is the sameas the extending direction of the data line SGL for display, and arearranged in the row direction. The conductive wire 51 is formed at aposition that is overlapped with the drive electrode COML and notoverlapped with the pixel electrode 22. The conductive wire 51 includesa tab part 51 a projecting toward a position overlapping with the gateline GCL for display. At a position overlapped with the tab part 51 a,the gate line GCL for display is electrically coupled to the conductivewire 51 via a contact hole H4. A gate line for display in the m-th rowis assumed to be a gate line GCL(m) for display, a data line for displayin the n-th column is assumed to be a data line SGL(n) for display, anda conductive wire in the n-th column is represented as a conductive wire51(n). The conductive wire 51(n) is coupled to the gate line GCL(m) fordisplay, the conductive wire 51(n+1) is coupled to a gate line GCL(m+1)for display, and the conductive wire 51(n+2) is coupled to a gate lineGCL(m+2) for display. In this way, the conductive wires 51 are coupledto different gate lines GCL for display, respectively.

The conductive wire 51 is coupled to the gate driver 12 arranged in theframe region 10 b. The gate driver 12 includes shift registers SR<n>,SR<n+1>, SR<n+2>, SR<n+3>, and SR<n+4>. The conductive wires 51(n),51(n+1), 51(n+2), 51(n+3), and 51(n+4) are coupled to the shiftregisters SR<n>, SR<n+1>, SR<n+2>, SR<n+3>, and SR<n+4>, respectively.The gate driver 12 sequentially scans the conductive wires 51, andsupplies the scanning signal Vscan to a selected conductive wire 51. Thescanning signal Vscan is transmitted to the gate line GCL for displayvia the conductive wire 51, and supplied to a plurality of switchingelements TrD for display coupled to the gate line GCL for display. Theswitching element TrD for display is switched between ON and OFF withthe scanning signal Vscan.

In the present embodiment, the conductive wire 51 is coupled to the gateline GCL for display, extends in a direction intersecting with the gateline GCL for display, and is drawn out to the short side of the frameregion 10 b. Thus, the gate driver 12 can be arranged on the short sideof the frame region 10 b. The present embodiment employs a configurationin which the gate driver 12 is arranged at a position on the same sideas the display control IC 19 of one pair of short side portions of theframe region 10 b. Alternatively, a configuration can be employed inwhich the gate driver 12 is arranged on a short side portion opposite toa side on which the display control IC 19 is arranged. Thisconfiguration can further reduce the width on the long side of the frameregion 10 b.

The conductive wire 51 is made of a metallic material that is at leastone of aluminum (Al), copper (Cu), silver (Ag), molybdenum (Mo), andalloy thereof. The conductive wire 51 may be a laminate obtained bylaminating a plurality of metallic materials using one or more of thesemetallic materials.

Next, with reference to FIGS. 18 and 19, the following describes acoupling structure between the conductive wire 51 and the switchingelement TrD for display. FIG. 18 is a plan view of the TFT substrate forexplaining a configuration of the sub-pixel. FIG. 19 is across-sectional view along the line XIX-XIX′ in FIG. 18.

As illustrated in FIG. 18, a longitudinal direction of the pixelelectrode 22 corresponds to the extending direction of the data line SGLfor display. The pixel electrode 22 includes a plurality of stripelectrodes 22 a and a connecting part 22 b. The strip electrodes 22 aeach extend in the extending direction of the data line SGL for display,and are arranged in the extending direction of the gate line GCL fordisplay. The connecting part 22 b connects ends of the strip electrode22 a with each other. The pixel electrode 22 is coupled to a drainelectrode 63 of the switching element TrD for display via a contact holeH1.

As illustrated in FIGS. 18 and 19, the switching element TrD for displayincludes a semiconductor layer 61, a source electrode 62, the drainelectrode 63, and a gate electrode 64. A light shielding layer 54 isarranged below the semiconductor layer 61.

As illustrated in FIG. 19, an insulating layer 58 a is arranged on theTFT substrate 21 while covering the light shielding layer 54. Thesemiconductor layer 61 is arranged on the insulating layer 58 a. Aninsulating layer 58 b is arranged on the semiconductor layer 61, and thegate line GCL for display is arranged on the insulating layer 58 b. Aninsulating layer 58 c is arranged on the gate line GCL for display, andthe drain electrode 63 and the data line SGL for display are arranged onthe insulating layer 58 c. An insulating layer 58 d is arranged on thedrain electrode 63 and the data line SGL for display, and the conductivewire 51 is arranged on the insulating layer 58 d. An insulating layer 58e is arranged on the conductive wire 51, and the drive electrode COML isarranged on the insulating layer 58 e. As described above, theinsulating layer 24 is arranged on the drive electrode COML, and thepixel electrode 22 is arranged on the insulating layer 24.

The semiconductor layer 61 is coupled to the drain electrode 63 via acontact hole H2. The semiconductor layer 61 is bent to intersect withthe gate line GCL for display multiple times in a plan view. A portionof the gate line GCL for display overlapped with the semiconductor layer61 functions as the gate electrode 64. The semiconductor layer 61extends to a position overlapped with the data line SGL for display, andis electrically coupled to the data line SGL for display via a contacthole H3. A portion of the data line SGL for display overlapped with thesemiconductor layer 61 functions as the source electrode 62.

As a material for the semiconductor layer 61, a known material such aspolysilicon and an oxide semiconductor can be used. For example, atransparent amorphous oxide semiconductor (TAOS) is used to improve acapability for retaining a voltage for video display for a long time(retaining rate), thereby improving display quality.

A channel part is arranged at a portion of the semiconductor layer 61overlapped with the gate electrode 64. It is preferred that the lightshielding layer 54 is arranged at a position overlapping with thechannel part, and has a larger area than that of the channel part. Dueto the light shielding layer 54, for example, light incident on thesemiconductor layer 61 from a backlight is shielded.

As illustrated in FIG. 18, the conductive wire 51 is arranged to beoverlapped with the data line SGL for display. The tab part 51 a isarranged at the intersecting part of the data line SGL for display andthe gate line GCL for display, and projects in a direction intersectingwith an extending direction of the conductive wire 51. The tab part 51 ais arranged at a position that is overlapped with the gate line GCL fordisplay and not overlapped with the data line SGL for display. The tabpart 51 a is electrically coupled to the gate line GCL for display viathe contact hole H4. In this way, the conductive wire 51 is electricallycoupled to the switching element TrD for display.

As described above, the conductive wire 51 is arranged in a layerdifferent from that of the drive electrode COML via the insulating layer58 e, and is coupled to the switching element TrD for display via thegate line GCL for display. The conductive wire 51 is used as a gate linefor supplying the scanning signal Vscan to the switching element TrD fordisplay, so that a degree of freedom of wiring arranged within thedisplay region 10 a can be improved. Accordingly, a degree of freedom ofdesign of a circuit and the like arranged in the frame region 10 b isimproved. For example, as illustrated in FIG. 17, the gate driver 12 onthe short side of the frame region 10 b is arranged so that the longside of the frame region 10 b can be narrowed.

In the present embodiment, the width of the conductive wire 51 is largerthan that of the data line SGL for display, so that the data line SGLfor display can be prevented from being visually recognized. Theembodiment is not limited thereto. The width of the conductive wire 51may be the same as that of the data line SGL for display, or smallerthan that of the data line SGL for display. The configuration is notlimited to the conductive wire 51 being arranged to be overlapped withall the data lines SGL for display. A configuration may be employed inwhich the conductive wire 51 is not overlapped with some of the datalines SGL for display.

The pixel electrode 22 illustrated in FIG. 18 is patterned in a stripshape, but the embodiment is not limited thereto. The pixel electrode 22may be formed in a flat plate shape. In this case, the drive electrodeCOML includes one or a plurality of strip electrodes, for example.Although the pixel electrode 22 is arranged on an upper layer side (aside closer to the liquid crystal layer) than the drive electrode COML,the drive electrode COML may be arranged on an upper layer side than thepixel electrode 22. The drive electrode COML and the pixel electrode 22may be arranged adjacent to each other on the same layer. For example,each of the drive electrode COML and the pixel electrode 22 is formed asa strip electrode, and the drive electrode COML and the pixel electrode22 may be arranged apart from each other without being overlapped witheach other in a plan view.

Second Embodiment

FIG. 20 is a plan view illustrating a pixel substrate according to asecond embodiment. As illustrated in FIG. 20, the drive electrodes COMLare arranged in a matrix in the display region 10 a of the TFT substrate21, and the pixel electrodes 22 are arranged in a matrix overlappingwith the drive electrodes COML. In the present embodiment, the displayregion 10 a is divided into a first display region 10 c and a seconddisplay region 10 d for driving control. The first display region 10 cis a region closer to the display control IC 19, and the second displayregion 10 d is a region that is adjacent to the first display region 10c and is distant from the display control IC 19 as compared with thefirst display region 10 c. A first gate driver 12A and a second gatedriver 12B are arranged in the frame region 10 b of the TFT substrate21. The first gate driver 12A and the second gate driver 12B arearranged on the long side of the frame region 10 b. Two first gatedrivers 12A are arranged with the first display region 10 c interposedtherebetween, and two second gate drivers 12B are arranged with thesecond display region 10 d interposed therebetween.

The first gate driver 12A sequentially selects one line (one horizontalline) of the sub-pixels SPix (refer to FIG. 14) in the first displayregion 106 as a display driving target. The second gate driver 12Bsequentially selects one line (one horizontal line) of the sub-pixelsSPix in the second display region 10 d as a display driving target. Thefirst gate driver 12A and the second gate driver 12B can be driven forscanning at the same time, so that the screen size of the display region10 a can be increased and definition of the sub-pixels SPix can beimproved.

FIG. 21 is a plan view for explaining a configuration of the pixelelectrode and the switching element for display according to the secondembodiment. FIG. 22 is a plan view of the TFT substrate for explaining aconfiguration of the sub-pixel in the first display region according tothe second embodiment. FIG. 23 is a cross-sectional view along the lineXXIII-XXIII′ in FIG. 22. FIG. 24 is a plan view of the TFT substrate forexplaining a configuration of the sub-pixel in the second display regionaccording to the second embodiment. FIG. 25 is a cross-sectional viewalong the line XXV-XXV′ in FIG. 24.

As illustrated in FIG. 21, the first gate driver 12A is coupled to theswitching element TrD for display via a first gate line GCL1 fordisplay. The second gate driver 12B is coupled to the switching elementTrD for display via a second gate line GCL2 for display. In the firstdisplay region 10 c, a first data line SGL1 for display extends in adirection intersecting with an extending direction of the first gateline GCL1 for display, and the switching element TrD for display iscoupled to the first data line SGL1 for display. The conductive wire 51is arranged at a position overlapping with the first data line SGL1 fordisplay. The conductive wire 51 extends over the first display region 10c and the second display region 10 d. The switching element TrD fordisplay in the second display region 10 d is coupled to the conductivewire 51 via a second data line SGL2 for display.

As illustrated in FIGS. 22 and 23, the configuration of the switchingelement TrD for display and the pixel electrode 22 according to thepresent embodiment is similar to that in the first embodiment. Theswitching element TrD for display in the first display region 10 c isarranged so that the semiconductor layer 61 intersects with the firstgate line GCL1 for display in a plan view. As illustrated in FIG. 23,the semiconductor layer 61 is coupled to the first data line SGL1 fordisplay via the contact hole H3. The conductive wire 51 is arranged tobe overlapped with the first data line SGL1 for display, and is notcoupled to the first gate line GCL1 for display and the first data lineSGL1 for display. That is, the conductive wire 51 is not coupled to theswitching element TrD for display in the first display region 10 c.

As illustrated in FIGS. 24 and 25, the switching element TrD for displayin the second display region 10 d is arranged so that the semiconductorlayer 61 intersects with the second gate line GCL2 for display in a planview. The semiconductor layer 61 is coupled to the second data line SGL2for display via the contact hole H3. The second data line SGL2 fordisplay is electrically coupled to the conductive wire 51 via a contacthole H5. In this way, the conductive wire 51 is coupled to the switchingelement TrD for display in the second display region 10 d. The seconddata line SGL2 for display is arranged apart from the first data lineSGL1 for display in the same layer as that of the first data line SGL1for display illustrated in FIG. 23. As illustrated in FIG. 21, thesecond data line SGL2 for display is arranged in each of the switchingelements TrD for display in the second display region 10 d, and theswitching elements TrD for display arranged in the column direction arecoupled to one conductive wire 51 via the second data line SGL2 fordisplay.

FIG. 26 is a plan view for explaining a coupling structure between thedisplay control IC and wires. As illustrated in FIG. 26, the first dataline SGL1 for display is coupled to the switching element TrD fordisplay in the first display region 10 c, and drawn out to the frameregion 10 b in which the display control IC 19 is arranged. The firstdata line SGL1 for display is coupled to the display control IC 19 via acoupling wire 37 a. The conductive wire 51 is coupled to the switchingelement TrD for display in the second display region 10 d, extends to beoverlapped with the first data line SGL1 for display in the firstdisplay region 10 c, and is drawn out to the frame region 10 b in whichthe display control IC 19 is arranged. The conductive wire 51 is coupledto coupling wire 37 b via a contact hole H6 in the frame region 10 b.The conductive wire 51 is coupled to the display control IC 19 via thecoupling wire 37 b. In this way, the switching element TrD for displayin the first display region 10 c and the switching element TrD fordisplay in the second display region 10 d are coupled to the one displaycontrol IC 19.

As described above, the conductive wire 51 according to the presentembodiment is used as a data line for display for supplying the pixelsignal Vpix to the switching element TrD for display in the seconddisplay region 10 d. Thus, when the display control IC 19 scans thefirst data line SGL1 for display and the conductive wire 51 at the sametime while supplying the pixel signal Vpix to each of the selected firstdata line SGL1 for display and a selected conductive wire 51, a displayoperation in the first display region 10 c and the second display region10 d can be performed at the same time. When the conductive wire 51 isused as the data line for display, a degree of freedom of wiring withinthe display region 10 a is improved, so that display driving suitablefor increasing the screen size of the display region 10 a and improvingdefinition of the sub-pixels SPix can be implemented.

The conductive wire 51 is overlapped with the first data line SGL1 fordisplay and the second data line SGL2 for display, and is longer thanthe first data line SGL1 for display and the second data line SGL2 fordisplay. Due to this, the first data line SGL1 for display and thesecond data line SGL2 for display can be made invisible.

In the present embodiment, the display region 10 a is divided into thefirst display region 10 c and the second display region 10 d, and theconductive wire 51 is coupled to the switching element TrD for displayon the second display region 10 d side. However, the embodiment is notlimited thereto. For example, the data line SGL for display may becoupled to the switching element TrD for display in an odd numbercolumn, and the conductive wire 51 may be coupled to the switchingelement TrD for display in an even number column. In this case, the dataline SGL for display and the conductive wire 51 may be coupled todifferent scanning driving units, and a display operation may beperformed for every two lines including one data line SGL for displayand one conductive wire 51 at the same time.

Third Embodiment

FIG. 27 is a plan view for explaining a coupling structure between thedrive electrode and a switching element for touch according to a thirdembodiment. As illustrated in FIG. 27, in the touch panel 30 accordingto the present embodiment, a gate line GCLT for touch is arranged to beoverlapped with the drive electrode block COMLA including the driveelectrodes COML arranged in the row direction. The gate line GCLT fortouch is arranged corresponding to each of a plurality of driveelectrode blocks COMLA arranged in the column direction. An end of thegate line GCLT for touch is coupled to the gate driver 12 (a gate driver12C for touch).

Two conductive wires 52A and 52B are arranged corresponding to one driveelectrode COML. The conductive wires 52A and 52B extend in parallel witheach other in a direction intersecting with the gate line GCLT fortouch, that is, the column direction while being overlapped with thedrive electrodes COML arranged in the column direction. Ends of theconductive wires 52A and 52B are coupled to the drive electrode driver14.

A first switching element TrT1 for touch is arranged at a portion wherethe gate line GCLT for touch intersects with the conductive wire 52A,and a second switching element TrT2 for touch is arranged at a portionwhere the gate line GCLT for touch intersects with the conductive wire52B. Two TFT elements (the first switching element TrT1 for touch andthe second switching element TrT2 for touch) are arranged correspondingto one drive electrode COML, and one gate line GCLT for touch is coupledto the first switching element TrT1 for touch and the second switchingelement TrT2 for touch corresponding to one drive electrode COML.

The first switching element TrT1 for touch and the second switchingelement TrT2 for touch perform switching operations reverse to eachother. When the same scanning signal is supplied to the first switchingelement TrT1 for touch and the second switching element TrT2 for touch,and the scanning signal is at a high level, for example, the firstswitching element TrT1 for touch is turned ON (opened), and the secondswitching element TrT2 for touch is turned OFF (closed). When thescanning signal is at a low level, the first switching element TrT1 fortouch is turned OFF (closed), and the second switching element TrT2 fortouch is turned ON (opened). For example, the first switching elementTrT1 for touch is an n-type TFT element, and the second switchingelement TrT2 for touch is a p-type TFT element.

As illustrated in FIG. 27, the drive electrode driver 14 includes adrive signal generation unit 14A that generates the drive signal, andwires LAC and LDC. The drive signal generation unit 14A generates thetouch drive signal Vcomac for touch detection, and the display drivesignal Vcomdc having a common potential for the display operation. Thedrive signal generation unit 14A outputs the touch drive signal Vcomacto the wire LAC, and outputs the display drive signal Vcomdc to the wireLDC.

The wire LAC is coupled to the conductive wire 52A. The touch drivesignal Vcomac is supplied to the first switching element TrT1 for touchvia the conductive wire 52A. The wire LDC is coupled to the conductivewire 52B. The display drive signal Vcomdc is supplied to the secondswitching element TrT2 for touch via the conductive wire 52B.

The gate driver 12 includes shift registers SR, and the gate lines GCLT(n), GCLT(n+1), and GCLT(n+2) for touch are coupled to the shiftregisters SR<n>, SR<n+1>, and SR<n+2>, respectively. The gate driver 12scans the gate line GCLT for touch, and a scanning drive signal issupplied to a selected gate line GCLT for touch. The first switchingelement TrT1 for touch coupled to the selected gate line GCLT for touchis turned ON, and the second switching element TrT2 for touch coupledthereto is turned OFF. Accordingly, the touch drive signal Vcomac issupplied to the drive electrode COML (drive electrode block COMLA)overlapped with the selected gate line GCLT for touch via the conductivewire 52A.

The first switching element TrT1 for touch coupled to a non-selectedgate line GCLT for touch is turned OFF, and the second switching elementTrT2 for touch coupled thereto is turned ON. Accordingly, the touchdrive signal Vcomac is not supplied to the drive electrode COML (driveelectrode block COMLA) overlapped with the non-selected gate line GCLTfor touch, and the display drive signal Vcomdc is supplied thereto viathe conductive wire 52B.

When the gate driver 12 sequentially selects the gate line GCLT fortouch, and the drive electrode driver 14 supplies the touch drive signalVcomac to the drive electrode COML (drive electrode block COMLA) coupledto the selected gate line GCLT for touch, contact or proximity of anexternal conductor can be detected based on the principle of mutualcapacitance touch detection described above.

Next, the following describes a coupling structure between the driveelectrode COML and the conductive wires 52A and 52B. FIG. 28 is a planview for explaining a configuration of the drive electrode and the pixelelectrode according to the third embodiment. FIG. 29 is across-sectional view along the line XXIX-XXIX′ in FIG. 28.

As illustrated in FIG. 28, a plurality of pixel electrodes 22 arearranged to be overlapped with one drive electrode COML. The pixelelectrodes 22 are coupled to the gate line GCL for display and the dataline SGL for display via the switching element TrD for display. In FIG.28, five columns of pixel electrodes 22 are arranged for one driveelectrode COML, but the embodiment is not limited thereto. Six or morecolumns of pixel electrodes 22 may be arranged, or four or less columnsof pixel electrodes 22 may be arranged. The configuration of theswitching element TrD for display according to the present embodiment issimilar to that of the first embodiment and the second embodiment,except that the conductive wires 52A and 52B are not coupled to the gateline GCL for display, and the conductive wires 52A and 52B are notcoupled to the data line SGL for display.

As illustrated in FIG. 28, the gate line GCLT for touch is arrangedalong one gate line GCL for display. The gate line GCLT for touchextends in the row direction, and is arranged at a position notoverlapped with the pixel electrode 22 between the pixel electrodes 22adjacent to each other in the column direction. The conductive wire 52Ais arranged to be overlapped with one data line SGL for display. Theconductive wiring 52A extends in the column direction while intersectingwith the gate line GCLT for touch. The conductive wire 52B is arrangedto be overlapped with the data line SGL for display at a positiondifferent from that of the conductive wire 52A. The conductive wire 52Bextends in the column direction while intersecting with the gate lineGCLT for touch. The conductive wire 52A and the conductive wire 52B areformed at a position that is overlapped with the drive electrode COMLand not overlapped with the pixel electrode 22.

The conductive wire 52A includes a tab part 52 a projecting toward aposition not overlapped with the data line SGL for display. Theconductive wire 52A is coupled to the first switching element TrT1 fortouch via the tab part 52 a. Similarly, the conductive wire 52B includesa tab part 52 b projecting toward a position not overlapped with thedata line SGL for display. The conductive wire 52B is coupled to thesecond switching element TrT2 for touch via the tab part 52 b.

As illustrated in FIG. 29, the first switching element TrT1 for touchincludes a semiconductor layer 71, a source electrode 72, a drainelectrode 73, and a gate electrode 74. The second switching element TrT2for touch includes a semiconductor layer 81, a source electrode 82, adrain electrode 83, and a gate electrode 84.

An end of the semiconductor layer 71 in the first switching element TrT1for touch is coupled to the source electrode 72 via a contact hole HT2.The source electrode 72 is coupled to the conductive wire 52A via acontact hole HT1. The other end of the semiconductor layer 71 is coupledto the drain electrode 73 via a contact hole HT3. The drain electrode 73is coupled to the drive electrode COML via a contact hole HT4. The gateline GCLT for touch at a portion overlapped with the semiconductor layer71 functions as the gate electrode 74. In this way, the conductive wire52A is coupled to the drive electrode COML via the first switchingelement TrT1 for touch.

An end of the semiconductor layer 81 in the second switching elementTrT2 for touch is coupled to the source electrode 82 via a contact holeHT6. The source electrode 82 is coupled to the conductive wire 52B via acontact hole HT5. The other end of the semiconductor layer 81 is coupledto the drain electrode 83 via a contact hole HT7. The drain electrode 83is coupled to the drive electrode COML via a contact hole HT8. The gateline GCLT for touch at a portion overlapped with the semiconductor layer81 functions as the gate electrode 84. In this way, the conductive wire52B is coupled to the drive electrode COML via the second switchingelement TrT2 for touch.

The semiconductor layer 71 and the semiconductor layer 81 are arrangedin the same layer as the semiconductor layer 61 of the switching elementTrD for display, and on the insulating layer 58 a. The insulating layer58 b is arranged on the semiconductor layer 61, the semiconductor layer71, and the semiconductor layer 81. The gate electrode 74 and the gateelectrode 84 (gate lines GCLT for touch) are arranged in the same layeras the gate electrode 64 (gate line GCL for display) of the switchingelement TrD for display, and on the insulating layer 58 b. Theinsulating layer 58 c is arranged on the gate electrode 64, the gateelectrode 74, and the gate electrode 84. The source electrode 72, thedrain electrode 73, the source electrode 82, and the drain electrode 83are arranged in the same layer as the source electrode 62 and the drainelectrode 63 of the switching element TrD for display, and on theinsulating layer 58 c. The insulating layer 58 d is arranged on thesource electrode 62, the drain electrode 63, the source electrode 72,the drain electrode 73, the source electrode 82, and the drain electrode83.

The conductive wire 52A and the conductive wire 52B are arranged on theinsulating layer 58 d, and the insulating layer 58 e is arranged on theconductive wire 52A and the conductive wire 52B. The drive electrodeCOML is arranged on the insulating layer 58 e. That is, the conductivewire 52A and the conductive wire 52B are arranged in a layer differentfrom that of the drive electrode COML via the insulating layer 58 e. Theconductive wire 52A and the conductive wire 52B are arranged in the samelayer, but the embodiment is not limited thereto. The conductive wire52A and the conductive wire 52B may be arranged in different layers. Thefirst switching element TrT1 for touch and the second switching elementTrT2 for touch are arranged in the same layer as the switching elementTrD for display, but the embodiment is not limited thereto. The firstswitching element TrT1 for touch and the second switching element TrT2for touch may be arranged in a layer different from that of theswitching element TrD for display. In view of visibility, the firstswitching element TrT1 for touch and the second switching element TrT2for touch are preferably arranged in the sub-pixel SPix corresponding tothe color region 32B of blue described above.

Next, the following describes an example of a driving method accordingto the present embodiment. FIG. 30 is a timing waveform chartillustrating an operation example of the display device with a touchdetection function according to the third embodiment. As illustrated inFIG. 30, the display periods Pd1, Pd2, Pd3 . . . and the touch periodsPt1, Pt2, Pt3 . . . are alternately arranged in a time division manner.In the display periods Pd1, Pd2, Pd3 . . . , the scanning signal Vscanis OFF (at a low level), the first switching element TrT1 for touch ineach drive electrode COML illustrated in FIG. 27 is turned OFF (closed),and the second switching element TrT2 for touch therein is turned ON(opened). Due to this, the display drive signal Vcomdc is supplied toeach drive electrode COML via the conductive wire 52B.

In the touch period Pt1, the gate line GCLT(n) for touch in the n-th rowis selected, and the scanning signal Vscan(n) is turned ON (high level).The first switching element TrT1 for touch of a drive electrode blockCOMLA(n) in the n-th row is turned ON (opened), and the second switchingelement TrT2 for touch thereof is turned OFF (closed). Due to this, thetouch drive signal Vcomac is supplied to each drive electrode COML inthe drive electrode block COMLA(n) via the conductive wire 52A. Based onthe principle of mutual capacitance touch detection, the touch detectionsignal Vdet1 is output from the touch detection electrode TDL (refer toFIG. 13) to the touch detection unit 40 (refer to FIG. 1). In the touchperiod Pt1, the scanning signal Vscan is OFF (low level) in the gatelines GCLT for touch other than the gate line GCLT(n) for touch, and thedisplay drive signal Vcomdc is supplied to each drive electrode COML viathe conductive wire 52B.

In the touch period Pt2, a gate line GCLT(n+1) for touch in the (n+1)-throw is selected, and a scanning signal Vscan(n+1) is turned ON (highlevel). The first switching element TrT1 for touch of a drive electrodeblock COMLA(n+1) in the (n+1)-th row is turned ON (opened), and thesecond switching element TrT2 for touch thereof is turned OFF (closed).Due to this, the touch drive signal Vcomac is supplied to each driveelectrode COML in the drive electrode block COMLA(n+1) via theconductive wire 52A.

In the touch period Pt3, a gate line GCLT(n+2) for touch in the (n+2)-throw is selected, and a scanning signal Vscan(n+2) is turned ON (highlevel). The first switching element TrT1 for touch of a drive electrodeblock COMLA(n+2) in the (n+2)-th row is turned ON (opened), and thesecond switching element TrT2 for touch thereof is turned OFF (closed).Due to this, the touch drive signal Vcomac is supplied to each driveelectrode COML in the drive electrode block COMLA(n+2) via theconductive wire 52A. These processes are sequentially repeated toperform a touch detection operation of the entire touch detectionsurface.

As described above, in the present embodiment, the touch drive signalVcomac as a drive signal for touch detection is supplied to the driveelectrode COML via the conductive wire 52A. The display drive signalVcomdc having a common potential for the pixel electrode 22 is suppliedto the drive electrode COML via the conductive wire 52B. Accordingly, bysequentially scanning the drive electrodes COML arranged in a matrix,contact or proximity of an external conductor can be detected based onthe basic principle of mutual capacitance touch detection.

Each of the conductive wire 52A and the conductive wire 52B is arrangedto be overlapped with the data line SGL for display, so that an openingarea of the sub-pixel SPix can be prevented from being reduced ascompared with a case in which each of the conductive wire 52A and theconductive wire 52B is arranged in the same layer as the data line SGLfor display, or a case in which each of the conductive wire 52A and theconductive wire 52B is arranged at a position different from that of thedata line SGL for display. In FIGS. 27 and 28, employed is aconfiguration in which two wires including the conductive wire 52A andthe conductive wire 52B are arranged for the drive electrode COML ineach column. Alternatively, a configuration in which three or moreconductive wires are arranged along the pixel electrode 22 in eachcolumn may be employed. In this case, conductive wires other than theconductive wire 52A and the conductive wire 52B are arranged as dummywires that are overlapped with the data line SGL for display and are notelectrically coupled to the drive electrode COML. When the conductivewires are arranged along the pixel electrode 22 in each column,variation in arrangement pitch of the conductive wires can besuppressed, so that visibility can be improved.

The first switching element TrT1 for touch and the second switchingelement TrT2 for touch are switched to be coupled to or disconnectedfrom the drive electrode COML in opposite phases for the same scanningsignal. Due to this, the touch drive signal Vcomac and the display drivesignal Vcomdc can be securely supplied. A switch unit for switchingbetween supply of the touch drive signal Vcomac and supply of thedisplay drive signal Vcomdc is not required to be arranged in the frameregion 10 b, so that the frame can be narrowed.

FIG. 31 is a plan view illustrating a configuration example of the gatedriver according to the third embodiment. As illustrated in FIG. 31, thegate driver 12 includes the gate driver 12C for touch and a gate driver12D for display. The gate driver 12C for touch scans the gate line GCLTfor touch and supplies the scanning signal to a selected gate line GCLTfor touch. The gate driver 12D for display scans the gate line GCL fordisplay and supplies the scanning signal to a selected gate line GCL fordisplay. In this way, a configuration in which the gate driver 12C fortouch and the gate driver 12D for display are arranged can also beemployed.

FIG. 32 is a plan view illustrating another configuration example of thegate driver according to the third embodiment. As illustrated in FIG.32, the gate line GCLT for touch and the gate line GCL for display arecoupled to one gate driver 12. The gate lines GCL for display arecoupled to the shift registers SR<n>, SR<n+1>, SR<n+3>, SR<n+4>, andSR<n+5> of the gate driver 12, and the gate line GCLT for touch iscoupled to the shift register SR<n+2>. In addition to the conductivewire 52A and the conductive wire 52B, a conductive wire 52C is arrangedto be overlapped with the data line SGL for display. A clock signal CLKgenerated in a clock signal generation unit 18 is supplied to the gatedriver 12 via the conductive wire 52C.

The gate driver 12 sequentially scans the gate line GCLT for touch andthe gate line GCL for display based on the clock signal CLK. The gatedriver 12 supplies the scanning signal Vscan to the gate line GCLT fortouch or the gate line GCL for display that is selected based on theclock signal CLK. The clock signal generation unit 18 is included in thecontrol unit 11 (refer to FIG. 1), and mounted on the display control IC19.

In this way, the conductive wire 52C is arranged in the display region10 a and used as a wire for supplying the clock signal CLK, so that thenumber of wires arranged in the frame region 10 b can be reduced and theframe can be narrowed.

FIG. 33 is a plan view illustrating a light shielding part of thedisplay device with a touch detection function according to amodification of the third embodiment. FIG. 34 is a cross-sectional viewalong the line XXXIV-XXXIV′ in FIG. 33.

In the present modification, a light shielding part 38 is arranged abovethe gate line GCL for display and the data line SGL for display (referto FIG. 31). As illustrated in FIG. 33, the light shielding part 38includes a first light shielding part 38 a extending in the rowdirection and a second light shielding part 38 b extending in adirection intersecting with an extending direction of the first lightshielding part 38 a, and the first light shielding part 38 a and thesecond light shielding part 38 b are arranged in a gridlike fashion. Thefirst light shielding part 38 a overlaps with the gate line GCL fordisplay, and the second light shielding part 38 b overlaps with the dataline SGL for display. A region surrounded by the first light shieldingpart 38 a and the second light shielding part 38 b is an opening region39.

As illustrated in FIG. 34, the light shielding part 38 is arranged on asurface of the TFT substrate 21 side of the glass substrate 31. Thelight shielding part 38 is arranged in the same layer as the colorfilter 32. The color filter 32 is arranged at a position correspondingto the opening region 39 illustrated in FIG. 33 while being overlappedwith the pixel electrode 22. With the light shielding part 38, the gateline GCL for display, the data line SGL for display, the switchingelement TrD for display, the first switching element TrT1 for touch, andthe second switching element TrT2 for touch can be prevented from beingvisually recognized.

As illustrated in FIG. 34, an orientation film 33 is arranged betweenthe liquid crystal layer 6, and the light shielding part 38 and thecolor filter 32. An orientation film 34 is arranged between the pixelelectrode 22 on the TFT substrate 21 side and the liquid crystal layer6. A spacer 26 is arranged between the TFT substrate 21 and the glasssubstrate 31 to keep a gap between the TFT substrate 21 and the glasssubstrate 31. As illustrated in FIG. 33, the spacer 26 is arranged inthe vicinity of an intersecting part 38X of the first light shieldingpart 38 a and the second light shielding part 38 b in a plan view.

In the present modification, the intersecting part 38X overlapped withthe spacer 26 has, for example, a circular shape in a plan view, and hasa larger area than that of an intersecting part not overlapped with thespacer 26 between the first light shielding part 38 a and the secondlight shielding part 38 b. The first switching element TrT1 for touchand the second switching element TrT2 for touch are arranged to beoverlapped with the spacers 26 and 26, respectively, in a plan view.Thus, the first switching element TrT1 for touch and the secondswitching element TrT2 for touch are arranged to be overlapped with theintersecting part 38X, so that the first switching element TrT1 fortouch and the second switching element TrT2 for touch can be preventedfrom being visually recognized from the outside. The first switchingelement TrT1 for touch and the second switching element TrT2 for touchare arranged by utilizing a region in which the spacers 26 and 26 arearranged, so that an area of the opening region 39 can be prevented frombeing reduced.

Fourth Embodiment

FIG. 35 is a plan view illustrating a configuration example of the driveelectrode and the drive electrode driver according to a fourthembodiment. FIG. 36 is a cross-sectional view illustrating a couplingpoint between the drive electrode and the conductive wire.

The present embodiment is different from the third embodiment in thatthe first switching element TrT1 for touch and the second switchingelement TrT2 for touch are not arranged in the drive electrode COML. Asillustrated in FIG. 35, a conductive wire 53A is coupled to each driveelectrode COML in the drive electrode block COMLA(n) in the n-th row. Aconductive wire 53B is coupled to each drive electrode COML in the driveelectrode block COMLA(n+1) in the (n+1)-th row. A conductive wire 53C iscoupled to each drive electrode COML in the drive electrode blockCOMLA(n+2) in the (n+2)-th row.

As illustrated in FIG. 36, the insulating layer 58 e is arranged betweenthe conductive wire 53A and the drive electrode COML. The conductivewire 53A is electrically coupled to the drive electrode COML via acontact hole H7 arranged in the insulating layer 58 e. The conductivewires 53B and 53C (not illustrated in FIG. 36) are also electricallycoupled to the drive electrode COML. The switching element TrD fordisplay has the same configuration as that described above, but is notelectrically coupled to the conductive wires 53A, 53B, and 53C.

Each of the conductive wires 53A, 53B, and 53C extends while overlappingwith the data line SGL for display (refer to FIG. 31), and is coupled tothe drive electrode driver 14. The drive electrode driver 14 includesthe drive signal generation unit 14A, a drive electrode scanning unit14B, the wires LAC and LDC, and switches SW1 and xSW1. A plurality ofconductive wires 53A are coupled to one set of the switches SW1 andxSW1, and a plurality of conductive wires 53B and a plurality ofconductive wires 53C are also coupled to the different switches SW1 andxSW1.

As illustrated in FIG. 35, the switch SW1 and the switch xSW1 areswitched to be ON and OFF in opposite phases. The switches SW1 and xSW1are sequentially selected by the drive electrode scanning unit 14B, andthe scanning signal is supplied to the selected set of switches SW1 andxSW1. When the scanning signal is supplied to the switches SW1 and xSW1from the drive electrode scanning unit 14B, the switch SW1 is turned OFFand the switch xSW1 is turned ON. When the scanning signal is notsupplied, the switch SW1 is turned ON, and the switch xSW1 is turnedOFF.

Each of the switches SW1 is coupled to the wire LDC, and receives thedisplay drive signal Vcomdc supplied from the drive signal generationunit 14A. Each of the switches xSW1 is coupled to the wire LAC, andreceives the touch drive signal Vcomac supplied from the drive signalgeneration unit 14A. When the scanning signal is supplied to one set ofswitches SW1 and xSW1 coupled to the conductive wire 53A, the switchxSW1 is turned ON, and the touch drive signal Vcomac is supplied to thedrive electrode COML in the drive electrode block COMLA(n) via theconductive wire 53A. When the drive electrode scanning unit 14Bsequentially scans the switches SW1 and xSW1, the touch drive signalVcomac is sequentially supplied to the drive electrode blocks COMLA(n+1)and COMLA(n+2) via the conductive wires 53B and 53C. Thus, touchdetection is performed based on the principle of mutual capacitancetouch detection described above.

When the switches SW1 and xSW1 are not selected by the drive electrodescanning unit 14B, the switch SW1 is turned ON, and the display drivesignal Vcomdc is supplied to each drive electrode COML via theconductive wires 53A, 53B, and 53C.

With such a configuration, by sequentially scanning the drive electrodesCOML arranged in a matrix, contact or proximity of an external conductorcan be detected based on the basic principle of mutual capacitance touchdetection. In the present embodiment, each of the conductive wires 53A,53B, and 53C is coupled to each drive electrode COML, so that the numberof wires within the display region 10 a can be reduced as compared withthe third embodiment.

Fifth Embodiment

FIG. 37 is a plan view of the drive electrode and a drive circuitaccording to a fifth embodiment. The configuration of the driveelectrode COML, the gate line GCLT for touch, the conductive wires 52Aand 52B, the first switching element TrT1 for touch, the secondswitching element TrT2 for touch, and the gate driver 12 according tothe present embodiment is similar to the configuration illustrated inFIG. 27. The display device with a touch detection function according tothe present embodiment detects contact or proximity of an externalconductor based on self capacitance of the drive electrode COML.

As illustrated in FIG. 37, the drive signal generation unit 14A suppliesthe touch drive signal Vcomac to the conductive wire 52A. The touchdrive signal Vcomac is supplied to the drive electrode COML via theconductive wire 52A and the first switching element TrT1 for touch.Accordingly, based on the principle of self capacitance touch detectiondescribed above, a detection signal corresponding to the selfcapacitance of the drive electrode COML is output to the touch detectionunit 40 via the conductive wire 52A, and the touch detection signalVdet2 is output.

The drive signal generation unit 14A supplies the display drive signalVcomdc to the wire LDC, and supplies a signal Vsgl to wire LGC. Theconductive wire 52B is coupled to the wire LDC via the switch SW1, andcoupled to the wire LGC via the switch xSW1. The switch SW1 is coupledto a wire LS1, and the switch xSW1 is coupled to a wire LS2. The switchSW1 and the switch xSW1 are switched between ON and OFF based on switchsignals supplied from the wire LS1 and the wire LS2, respectively. Theswitch signals supplied from the wire LS1 and the wire LS2 are inopposite phases, controlling the switch SW1 and the switch xSW1 to be ONand OFF in an opposite manner.

When the second switching element TrT2 for touch is in an ON state andthe switch SW1 is turned ON, the display drive signal Vcomdc is suppliedto the drive electrode COML via the conductive wire 52B. When the secondswitching element TrT2 for touch is in the ON state and the switch xSW1is turned ON, the signal Vsgl is supplied to the drive electrode COMLvia the conductive wire 52B. The signal Vsgl preferably has the samewaveform synchronized with the touch drive signal Vcomac.

With such a configuration, the display drive signal Vcomdc is suppliedto the drive electrode COML in a display operation. When touch detectionis performed, the touch drive signal Vcomac is supplied to the driveelectrode COML selected as a detection target, and the signal Vsgl issupplied to the drive electrode COML that is not selected. When thesignal Vsgl is supplied, parasitic capacitance between the driveelectrode COML selected as a detection target and the non-selected driveelectrode COML is reduced, so that a detection error and deteriorationin detection sensitivity can be prevented.

FIG. 38 is a timing waveform chart illustrating an operation example ofthe display device with a touch detection function according to thefifth embodiment. As described above, in the display periods Pt1, Pt2 .. . , the scanning signal Vscan is not supplied to the gate line GCLTfor touch illustrated in FIG. 37, the first switching element TrT1 fortouch is turned OFF, and the second switching element TrT2 for touch isturned ON. Then the switch SW1 is turned ON, and the switch xSW1 isturned OFF. Accordingly, in each of the display periods Pt1, Pt2 . . . ,the display drive signal Vcomdc is supplied to the drive electrode COML.

In the touch period Pt1, the gate line GCLT(n) for touch in the n-th rowis selected by the gate driver 12, and the scanning signal Vscan(n) issupplied thereto. The first switching element TrT1 for touch coupled tothe gate line GCLT(n) for touch is turned ON, and the second switchingelement TrT2 for touch is turned OFF. The touch drive signal Vcomac issupplied to each of the drive electrodes COML in the drive electrodeblock COMLA(n) in the n-th row via the conductive wire 52A. Each driveelectrode COML in the drive electrode block COMLA(n) outputs a detectionsignal corresponding to self capacitance thereof to the touch detectionunit 40 via the conductive wire 52A.

In the touch period Pt1, the first switching element TrT1 for touchcoupled to the non-selected gate lines GCLT(n+1) and GCLT(n+2) for touchis turned OFF, and the second switching element TrT2 for touch coupledthereto is turned ON. Operations of the switches SW1 and xSW1 arereversed from the state in the display period Pt1, that is, the switchSW1 is turned OFF and the switch xSW1 is turned ON. Accordingly, thesignal Vsgl is supplied to the drive electrode blocks COMLA(n+1) andCOMLA(n+2) that are not selected as a detection target.

In the touch period Pt2, the gate line GCLT(n+1) for touch in the(n+1)-th row is selected by the gate driver 12, and the touch drivesignal Vcomac is supplied to each of the drive electrodes COML in thedrive electrode block COMLA(n+1) in the (n+1)-th row via the conductivewire 52A. The signal Vsgl is supplied to the drive electrode blocksCOMLA(n) and COMLA(n+2) that are not selected as a detection target.

In the touch period Pt3, the gate line GCLT(n+2) for touch in the(n+2)-th row is selected by the gate driver 12, and the touch drivesignal Vcomac is supplied to each of the drive electrodes COML in thedrive electrode block COMLA(n+2) in the (n+2)-th row via the conductivewire 52A. The signal Vsgl is supplied to the drive electrode blocksCOMLA(n) and COMLA(n+1) that are not selected as a detection target.

In this way, by sequentially selecting the drive electrode block COMLAto be a detection target in the touch periods Pt1 and Pt2 . . . , a selfcapacitance touch detection operation is performed on the entire touchdetection surface.

According to the present embodiment, by arranging the conductive wires52A and 52B coupled to the switching element for touch, the touch drivesignal Vcomac, the display drive signal Vcomdc, and the signal Vsgl canbe supplied to the drive electrode COML. The number of wires can bereduced as compared with a case in which each of wire is coupled to eachof the drive electrodes COML.

In the touch periods Pt1 and Pt2 . . . using a self capacitance system,the signal Vsgl may be supplied to the gate line GCL for display and thedata line SGL for display (not illustrated in FIG. 37). The gate lineGCL for display and the data line SGL for display may be in a floatingstate in which a fixed electric potential is not supplied. Accordingly,parasitic capacitance between the drive electrode COML and the gate lineGCL for display, and parasitic capacitance between the drive electrodeCOML and the data line SGL for display can be reduced.

FIG. 39 is a plan view illustrating a configuration example of the driveelectrode and the conductive wire according to a modification of thefifth embodiment. The drive electrode block COMLA in FIG. 37 includes arow of drive electrodes COML arranged in the row direction, but theembodiment is not limited thereto. As illustrated in FIG. 39, the gateline GCLT for touch coupled to the gate driver 12 extends while beingoverlapped with a row of drive electrodes COML. The gate line GCLT fortouch is bent on an opposite side of the gate driver 12 with the driveelectrode COML interposed therebetween, and extends while beingoverlapped with the next row of drive electrodes COML. In this way, tworows of drive electrodes COML may be coupled to one gate line GCLT fortouch, and the drive electrode block COMLA may include two rows of driveelectrodes COML.

Two conductive wires 52A and 52A and two conductive wires 52B and 52Bare coupled to a plurality of drive electrodes COML arranged in thecolumn direction. The conductive wire 52A is coupled to one driveelectrode COML for one drive electrode block COMLA. The conductive wire52B is coupled to one drive electrode COML for one drive electrode blockCOMLA. That is, the drive electrodes COML and COML adjacent to eachother in the column direction within the drive electrode block COMLA arecoupled to different conductive wires 52A and 52A and conductive wires52B and 52B.

The touch drive signal Vcomac is supplied to each drive electrode COMLfrom the drive signal generation unit 14A via the conductive wire 52A.The drive electrode COML then supplies the output signal to the touchdetection unit 40 via the conductive wire 52A. The wire LDC is coupledto each conductive wire 52B via the switch SW1, and the wire LGC iscoupled thereto via the switch xSW1. Accordingly, the display drivesignal Vcomdc and the signal Vsgl are supplied to the conductive wire52B. Thus, similarly to the operation example illustrated in FIG. 38, inthe touch periods Pt1 and Pt2 . . . , self capacitance touch detectioncan be performed by sequentially scanning the drive electrode blocksCOMLA(n), COMLA(n+1), and COMLA(n+2).

In the present embodiment, touch detection can be performed for thedetection electrode block COMLA including two rows of drive electrodesCOML in one touch period, so that detection time for the entire touchdetection surface can be reduced. In the present embodiment, the driveelectrode COML has a rectangular shape obtained by dividing the driveelectrode COML having a square shape illustrated in FIG. 37, forexample, into two parts including an upper part and a lower part.Alternatively, the drive electrode COML having a square shapeillustrated in FIG. 37, for example, can naturally be employed.

Sixth Embodiment

FIG. 40 is a block diagram illustrating a configuration example of thedisplay device with a touch detection function according to a sixthembodiment. A display device 1A with a touch detection functionaccording to the present embodiment can switch between mutualcapacitance touch detection and self capacitance touch detection to beperformed. As illustrated in FIG. 40, the touch detection unit 40includes a touch detection signal amplification unit 42A to which thetouch detection signal Vdet1 using a mutual capacitance system issupplied, an A/D conversion unit 43A, a signal processing unit 44A, anda coordinate extracting unit 45A. The touch detection unit 40 furtherincludes a touch detection signal amplification unit 42B to which thetouch detection signal Vdet2 using a self capacitance system issupplied, an A/D conversion unit 43B, a signal processing unit 44B, anda coordinate extracting unit 45B. The mutual capacitance touch detectionand the self capacitance touch detection can be switched based on thecontrol signal of the control unit 11.

FIG. 41 is a plan view of the drive electrode and the drive circuitaccording to the sixth embodiment. FIG. 42 is a timing waveform chartillustrating an operation example of the display device with a touchdetection function according to the sixth embodiment. The configurationof the drive electrode COML, the gate line GCLT for touch, theconductive wires 52A and 52B, the first switching element TrT1 fortouch, the second switching element TrT2 for touch, and the gate driver12 according to the present embodiment is similar to that illustrated inFIG. 27.

As illustrated in FIG. 41, the touch drive signal Vcomac is supplied tothe conductive wire 52A via the wire LAC. The switch SW2 is coupled tothe conductive wire 52A, and the switch SW2 is switched between ON andOFF based on a switch signal supplied from wire LS3. In a state in whichthe switch SW2 is ON, self capacitance touch detection is performed, andthe touch detection signal Vdet2 is output to the touch detection unit40 via the conductive wire 52A and the switch SW2. The wire LDC iscoupled to the conductive wire 52B via the switch SW1, and the wire LGCis coupled thereto via the switch xSW1. In a state in which the switchSW1 is ON and the switch xSW1 is OFF, the display drive signal Vcomdc issupplied to the conductive wire 52B. In a state in which the switch SW1is OFF and the switch xSW1 is ON, the signal Vsgl is supplied to theconductive wire 52B.

The left figure of FIG. 42 is a timing waveform chart of selfcapacitance touch detection, and the right figure of FIG. 42 is a timingwaveform chart of mutual capacitance touch detection. As illustrated inthe left figure of FIG. 42, a self capacitance touch detection operationis performed similarly to FIG. 38. The touch drive signal Vcomac issequentially supplied to the selected drive electrode block COMLA. Inthe touch periods Pt1 and Pt2 . . . and display periods Pd1 and Pd2 . .. using a self capacitance system, the switch SW2 is in the ON state,and the touch detection signal Vdet2 is output to the touch detectionunit 40 via the conductive wire 52A.

The switches SW1 and xSW1 are switched to be ON and OFF between thetouch periods Pt1 and Pt2 . . . and the display periods Pd1 and Pd2 . .. using a self capacitance system. In the display periods Pd1 and Pd2 .. . , the switch SW1 is turned ON, the switch xSW1 is turned OFF, andthe display drive signal Vcomdc is supplied to the drive electrodeblocks COMLA(n), COMLA(n+1), and COMLA(n+2). In the touch periods Pt1and Pt2 . . . , the switch SW1 is turned OFF, the switch xSW1 is turnedON, and the signal Vsgl is supplied to the drive electrode block COMLAthat is not selected by the gate driver 12.

Next, when the control unit 11 (refer to FIG. 40) switches selfcapacitance touch detection to mutual capacitance touch detection, anoperation illustrated in the right figure of FIG. 42 is performed. Asillustrated in the right figure of FIG. 42, a mutual capacitance touchdetection operation according to the present embodiment is performedsimilarly to FIG. 30. That is, in touch periods Ptm1, Ptm2 . . . using amutual capacitance system, the touch drive signal Vcomac is sequentiallysupplied to the selected drive electrode block COMLA. In the mutualcapacitance touch detection operation, the switch SW2 is turned OFF, thetouch detection signal Vdet2 is not output from the conductive wire 52A,and the touch detection signal Vdet1 is output from the touch detectionelectrode TDL.

In the touch periods Ptm1, Ptm2 . . . and the display periods Pd1 andPd2 . . . using a mutual capacitance system, the switch SW1 is turnedON, and the switch xSW1 is turned OFF. Due to this, the signal Vsgl isnot supplied to the conductive wire 52B, and the display drive signalVcomdc is supplied to the non-selected drive electrode block COMLA.

As described above, the display device 1A with a touch detectionfunction according to the present embodiment can switch between selfcapacitance touch detection and mutual capacitance touch detection witha configuration in which the conductive wires 52A and 52B are coupled tothe drive electrode COML. Due to this, a detection system can beappropriately switched to improve detection accuracy in accordance withdifferent input operation methods and the external environment.

In the present embodiment, the same touch drive signal Vcomac issupplied to the conductive wire 52A in both of self capacitance touchdetection and mutual capacitance touch detection. Alternatively, a touchdrive signal having different amplitude and a different frequency may besupplied. In the touch periods Ptm1, Ptm2 . . . using a mutualcapacitance system, the display drive signal Vcomdc is supplied to thenon-selected drive electrode block COMLA. Alternatively, a floatingstate may be caused in which the voltage signal is not supplied to thenon-selected drive electrode block COMLA and electric potential is notfixed. In this case, a configuration may be employed in which thedisplay drive signal Vcomdc is not supplied to the wire LDC in the touchperiods Ptm1, Ptm2 . . . , or a configuration may be employed in which aswitch is added between the wire LDC and the conductive wire 52B todisconnect the wire LDC from the conductive wire 52B in the touchperiods Ptm1, Ptm2 . . . .

The preferred embodiments of the present invention have been describedabove. However, the present invention is not limited thereto. Contentdisclosed in the embodiments is merely an example, and variousmodifications can be made without departing from the gist of theinvention. The present invention naturally encompasses an appropriatemodification maintaining the gist of the invention.

For example, the shapes of the drive electrode COML, the touch detectionelectrode TDL, and the pixel electrode 22 are merely an example, and maybe variously modified. The number of conductive wires, the arrangementthereof, the shape thereof, and the like may be appropriately modified.The embodiments may be appropriately combined. For example, theconductive wire may be coupled to the gate line GCLT for touchillustrated in FIG. 27 similarly to the first embodiment to supply thescanning signal via the conductive wire.

What is claimed is:
 1. A display device comprising: a substrate; a plurality of first electrodes on the substrate; a plurality of second electrodes opposed to the first electrodes; a plurality of switching elements that are coupled to the first electrodes or the second electrodes; a data line that is coupled to the switching elements; and a conductive wire that overlaps with the data line; wherein the conductive wire is coupled to the switching elements via the data line and has a width wider than a width of the data line at a position where the conductive wire overlaps the data line.
 2. The display device according to claim 1, wherein the switching elements are coupled to the first electrodes, and the conductive wire supplies pixel signals to the first electrodes via the data line and the switching elements.
 3. The display device according to claim 1, wherein the switching elements are coupled to the second electrodes, and the conductive wire supplies a common potential to the second electrodes via the data line and the switching elements.
 4. The display device according to claim 1, wherein the switching elements are coupled to the second electrodes, and the conductive wire supplies a drive signal for touch detection to the second electrodes via the data line and the switching elements.
 5. The display device according to claim 1, wherein the switching elements are coupled to the second electrodes, and the conductive wire supplies: a common potential to the second electrodes via the data line and the switching elements in a display operation period; and a drive signal for touch detection to the second electrodes via the data line and the switching elements in a detection operation period.
 6. The display device according to claim 5, wherein the second electrodes are used as common electrodes in the display operation period, and used as drive electrodes for touch detection in the detection operation period.
 7. The display device according to claim 1, wherein the conductive wire is opposed to the second electrode via an insulating layer and is located between the substrate and the second electrode in a direction perpendicular to a main surface of the substrate.
 8. The display device according to claim 1, wherein the conductive wire and the data line extend in a same direction.
 9. The display device according to claim 1, wherein the conductive wire overlaps none of the first electrodes.
 10. A display device comprising: a substrate; a plurality of pixel electrodes on the substrate; a plurality of common electrodes opposed to the pixel electrodes; a plurality of switching elements that are coupled to the common electrodes; a data line that is coupled to the switching elements; and a conductive wire that overlaps with the data line, wherein the conductive wire is coupled to the switching elements via the data line, the conductive wire supplies: a common potential to the common electrodes via the data line and the switching elements in a display operation period; and a drive signal for touch detection to the second electrodes via the data line and the switching elements in a detection operation period, and the conductive wire has a width wider than a width of the data line at a position where the conductive wire overlaps the data line.
 11. The display device according to claim 10, wherein the conductive wire and the data line extend in a same direction.
 12. The display device according to claim 10, wherein the conductive wire overlaps none of the pixel electrodes.
 13. The display device according to claim 10, wherein the common electrodes are used as drive electrodes for touch detection in the detection operation period. 